This invention relates to systems for improving the growing environment for ornamental and food-producing plants, shrubs and crops, and relates more particularly to systems automatically operable to apply a cooling irrigational spray of water vapor to such plants, shrubs or crops to maintain the moisture level substantially at a preselectable value.
Most ornamental and food-producing plants and crops thrive best in a cool, moist environment. Low humidity, excessive heat, drying winds, and a lack of root moisture inhibit growth. As a result, many of these plants and crops can be cultivated only in certain geographical areas where weather suits their requirements or where artificial means are provided to suitably modify local weather. For example, greenhouses are often used to increase temperature and humidity; but they are relatively expensive and, unless carefully controlled, invite plant disease due to stagnant air, tendency to overheat on sunny days or excessive moisture with resultant rot or fungus. If greenhouse ventilators are opened to reduce overheating and the wind is blowing, humidity is difficult to control.
It has heretofore been proposed to provide misting nozzles or watering sprays controlled by timers set to turn water supply on at a certain time for a preselectable period of time. This can result in overwatering or underwatering, depending upon the ambient conditions upon which this human judgment is superimposed. If the water thus applied is excessive, water is wasted and rot or fungus may occur. If the water is inadequate, root or leaf damage may result.
There is a need for a system that is automatically operative to provide irrigation of the flexible degree actually needed and at the same time so control the moisture level that damage to roots and leaves due to excessive or inadequate heat or moisture is substantially eliminated and insect damage is minimized.